begin cleaning up mesh library layer so that it could be split someday

src/mesh/mesh-pb-constants.cpp

@@ -0,0 +1,66 @@
+#include "mesh-pb-constants.h"
+#include "FS.h"
+#include "configuration.h"
+#include <Arduino.h>
+#include <assert.h>
+#include <pb_decode.h>
+#include <pb_encode.h>
+
+/// helper function for encoding a record as a protobuf, any failures to encode are fatal and we will panic
+/// returns the encoded packet size
+size_t pb_encode_to_bytes(uint8_t *destbuf, size_t destbufsize, const pb_msgdesc_t *fields, const void *src_struct)
+{
+
+    pb_ostream_t stream = pb_ostream_from_buffer(destbuf, destbufsize);
+    if (!pb_encode(&stream, fields, src_struct)) {
+        DEBUG_MSG("Error: can't encode protobuf %s\n", PB_GET_ERROR(&stream));
+        assert(0); // FIXME - panic
+    } else {
+        return stream.bytes_written;
+    }
+}
+
+/// helper function for decoding a record as a protobuf, we will return false if the decoding failed
+bool pb_decode_from_bytes(const uint8_t *srcbuf, size_t srcbufsize, const pb_msgdesc_t *fields, void *dest_struct)
+{
+    pb_istream_t stream = pb_istream_from_buffer(srcbuf, srcbufsize);
+    if (!pb_decode(&stream, fields, dest_struct)) {
+        DEBUG_MSG("Error: can't decode protobuf %s, pb_msgdesc 0x%p\n", PB_GET_ERROR(&stream), fields);
+        return false;
+    } else {
+        return true;
+    }
+}
+
+/// Read from an Arduino File
+bool readcb(pb_istream_t *stream, uint8_t *buf, size_t count)
+{
+    bool status = false;
+#ifndef NO_ESP32
+    File *file = (File *)stream->state;
+
+    if (buf == NULL) {
+        while (count-- && file->read() != EOF)
+            ;
+        return count == 0;
+    }
+
+    status = (file->read(buf, count) == count);
+
+    if (file->available() == 0)
+        stream->bytes_left = 0;
+#endif
+    return status;
+}
+
+/// Write to an arduino file
+bool writecb(pb_ostream_t *stream, const uint8_t *buf, size_t count)
+{
+#ifndef NO_ESP32
+    File *file = (File *)stream->state;
+    // DEBUG_MSG("writing %d bytes to protobuf file\n", count);
+    return file->write(buf, count) == count;
+#else
+    return false;
+#endif
+}